Fiberization of wastepaper for a wide variety of purposes is well known. However, recently it has been discovered that wastepaper can be deinked by dry fiberization if the wastepaper is substantially completely fiberized to individual fibers and ink-containing fines. Such a process is disclosed in U.S. Pat. No. 4,668,339 to Terry, issued May 26, 1987, which is herein incorporated by reference. In further developing the process disclosed in the Terry patent it has been found that the operation of the fiberizer cannot be optimized for commercial operation unless the feed rate to the fiberizer is properly regulated in two respects.
First, the distribution of the shredded wastepaper in the inlet duct to the fiberizer must be relatively even over its cross-sectional area or at least concentrated in the center of the inlet duct. Otherwise the wastepaper tends to overload some portions of the fiberizer instead of being evenly distributed around the entire periphery of the working surfaces of the fiberizer. This situation results in inefficient fiberizer operation and can result in some of the feed material being insufficiently fiberized to remove the ink or, alternatively, some of the feed material being over-fiberized causing undesirable damage to the fibers.
Second, the fiber/air ratio within the fiberizer must be maintained relatively constant. This can be difficult in large scale operations where the shredded wastepaper tends to be conveyed to the fiberizer in discontinuous clumps. This results in alternating overload/starvation circumstances within the fiberizer which is not conducive to high efficiency.
Therefore there is a need for a means of providing a fiberizer with an even feed distribution and feed rate.